Pheromone‐based mating disruption of the tea tussock moth, <scp> <i>Euproctis pseudoconspersa</i> </scp> , in <scp> <i>Camellia japonica</i> </scp> street trees

Abstract BACKGROUND The tea tussock moth, Euproctis pseudoconspersa , is a nuisance and defoliating pest of Camellia japonica , widely planted as street and windbreak trees. Pheromone‐based mating disruption (MD) is a low‐hazard alternative for urban settings; however, its performance in tall, dense canopies remains elusive. Herein, we investigated seasonal flight activity, vertical flight distribution and MD efficacy across 3 years (2023–2025) in roadside C. japonica stands in Jeju, Republic of Korea. RESULTS Pheromone monitoring of male moths showed two distinct flight periods per year. Furthermore, racemic 10,14‐dimethylpentadecyl isobutyrate consistently attracted males. Male capture inhibition (MCI) was 34.8% when MD dispensers were deployed only at 1.5 m. Contrastingly, vertically distributing dispensers within the canopy (≈1, 3 and 5 m) increased MCI to 84.2–95.8% across subsequent trials. In 2025, leaf damage was decreased from 10.5% (control) to 2.0% (MD), corresponding to 81.0% damage reduction. Dispensers released pheromone for &gt;60 days, whereas each male flight period lasted for ≈30 days. This indicates potential for decreasing pheromone loading to enhance cost‐efficiency without compromising disruption. CONCLUSION MD can effectively suppress E. pseudoconspersa in tall C. japonica street‐tree systems when dispensers are deployed at several canopy heights. Optimizing dispenser loading and enhancing deployment technologies (e.g. assisted canopy installation) may further improve feasibility in urban and forest environments. © 2026 Society of Chemical Industry.